VI PREFACE. 



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pect of a visit to Brazil, as a mere vacation it had little 

 charm for me. Single-handed, I could make slight use 

 of the opportunities I should have ; and though the ex- 

 cursion might be a pleasant one for myself, it would 

 have no important result for science. I could not forget 

 that, had I only the necessary means, I might make col- 

 lections on this journey which, whenever our building 

 could be so enlarged as to give room for their exhi- 

 bition, would place the Museum in Cambridge on a level 

 with the first institutions of the kind. But for this a 

 working force would be needed, and I saw no possibil- 

 ity of providing for such an undertaking. While I was 

 brooding over these thoughts I chanced to meet Mr. Na- 

 thaniel Thayer, whom I have ever found a generous friend 

 to science. The idea of appealing to him for a scheme 

 of this magnitude had not, however, occurred to me ; 

 but he introduced the subject, and, after expressing his 

 interest in my proposed journey, added, " You wish, of 

 course, to give it a scientific character ; take six assist- 

 ants with you, and I will be responsible for all their 

 expenses, personal and scientific." It was so simply said, 

 and seemed to me so great a boon, that at first I hardly 

 believed I had heard him rightly. In the end, I had 

 cause to see in how large and liberal a sense he proffered 

 his support to the expedition, which, as is usual in such 

 cases, proved longer and more costly than was at first 

 anticipated. Not only did he provide most liberally for 

 assistants, but, until the last specimen was stored in the 

 Museum, he continued to advance whatever sums were 



